Chōgen trained at Daigoji and Kōyasan, so he probably was formally a Shingon monk. But he was deeply influenced by Pure Land Buddhism and probably Kegonshū, as he was closely associated with Tōdai-ji, the head temple of Kegonshū (which is also mainly mikkyō). He lived some time as a hijiri, so I guess, that neither his robe nor his juzu are strictly "orthodox"...